The present invention relates to a new solder bath apparatus of soldering furnace, and more specifically, to a solder bath with a rotatable nozzle for adjusting flow of gushing molten solder.
With the continuing advances and developments of electrical manufactures, the electrical products in new generation have more developed and complicated capability to provide peoples more convenient and comfortable life. For instance, in computer industry, because the manufacture and packaging techniques of integrated circuits are promoted and matured, the high quality multimedia personal computers are widely used. The expenditure enhancement for computers and peripheral products cause the popularization and more vigorous development thereof. However, when the performances of chips are promoted, the amounts of leads to package components on the printed circuit boards (PCBs) also are continuously enhanced. Thus the layout of printed circuit boards becomes more fine and complex. And the difficulties to mount and solder components thereon are also enhanced.
In general, the key factor of the yields of mounting assembly parts onto printed circuit boards is the soldering procedure for mounting component leads. Especially when the amounts of leads are increased and the arrangement thereof become highly concentrated, the effective reductions of defects such as bridge, dewetting, blow hole, and etc., can promote the yields of PCBs productions and reduce the failure opportunities of components. In prior art the wave soldering procedures are mainly applied to assembly printed circuit boards for furthering mass productions. And in wave soldering process, the molten solder is driven by a motor pump and forced upward into the through holes beneath the printed circuit boards which are transported obliquely to pass the soldering wave via the transport means.
Please refer to FIG. 1, the current wave soldering system 10 is illustrated. In the wave soldering system 10, a solder bath 12 is applied to contain molten solder, and a motor pump 14 mounted beside the solder bath 12 can swing its fan blades to drive the molten solder. The molten solder gushed upwards from a nozzle 16 disposed in the solder bath 12 forms the rising solder wave. And printed circuit boards 20 can be transferred to pass over the solder bath 12 through inclined transport rails 18. Thus the rising solder wave can fill into the through holes beneath the printed circuit boards to solder the leads of components. It is noted that in the wave soldering procedure the printed circuit board 20 is disposed onto a carrier formed of aluminum alloy or fiberglass wherein the carrier has some hollows for exposing the soldering areas of the printed circuit board. Then the finger 22 chained beneath the transport rails 18 can grab two side of the carrier to transfer the printed circuit board 20 via the transport rails 18.
In general, the printed circuit board 20 is coated flux and preheated first in the front part 24 of the transport rails 18. The flux is applied to clean the surfaces of the soldering metal and to avoid rustiness in atmosphere at high temperature. Besides, the flux is also applied to spread thermal energy uniformly for enhancing the performance of the soldering points. The typical flux coating procedures include foaming type, spraying type, and soaking type. As to the subsequent preheat procedure is applied to dispel the volatility parts of the flux for promoting the temperatures of the printed circuit boards to enhance the flux activity and to prove the capability of filling molten solder into through holes. The typical preheating procedure is to apply infrared tubes beneath the carriers to illuminate the printed circuit boards to a predetermined temperature.
Please refer to FIG. 2, which illustrates the structure of the solder bath 12. The members of solder bath 12 include a nozzle base 26, a nozzle 16 and a motor pump 14. The solder bath 12 for containing molten solder has a horizontal partition 28 applied to divide the inner space of solder bath 12 into two rooms, the upper room and the lower room. And the partition 28 has a bar opening 30 through the upper and lower room on central part thereof. The nozzle base 26 is located on the opening 30, and the nozzle 16 is mounted on the nozzle base 26. Besides, the motor pump 14 disposed beside the solder bath 12 can swing the fan blades to drive molten solder gush from the nozzle 16 in solder bath 12 to form rising solder wave. Thus, when the printed circuit board 20 pass over the molten solder 24 via the inclined transport rails 18, the rising molten solder can fill the through holes beneath the printed circuit board 20 to form solder points.
However, due to the nozzle 16 in prior art is fastened on the nozzle base 26, the outlet direction of nozzle can not be adjusted, and there is no capability of controlling the solder wave of molten solder gushed therefrom. Therefore the yields of soldering process can not be promoted in advance. And the short circuits occurred on the printed circuit boards can not be eliminated as far as possible. So it is required to apply post-sodering procedures by manpower to reduce the defects on printed circuit boards. For solving this issue, associated manufacturing industries devote themselves to improve the structure of solder bath for promoting the soldering yields and throughput thereof effectively.
A purpose of the present invention is to provide a solder bath with rotatable nozzle to promote yields of soldering procedures.
Another purpose of the present invention is to provide a nozzle with axial pillars stretching horizonally to provide the operator for adjusting the outlet angle of nozzle by rotating it about the axial pillars.
Further a purpose of the present invention is to provide an enclosing frame with axial horizontal pillars for rotating the nozzle.
The present invention discloses a solder bath apparatus applied to the soldering furnace. The solder bath is used for containing molten solder. And a horizontal partition is disposed in the solder bath to divide space therein to an upper room and a lower room. The partition has a bar opening on the center thereof to pass through the lower room and the upper room. A nozzle base is located on the bar opening of the partition to gush molten solder upwards into the upper room. An enclosing frame with a bar-shaped structure is put around the nozzle base, and has axial horizontal pillars mounted on the two terminal sidewalls thereof. The nozzle is manufactured with two bearing pedestals on two terminal sidewalls responsive to the pillars, and is put around the enclosing frame. When the nozzle is put around the enclosing frame, the pillar can penetrate through the bearing pedestal to let nozzle rotate around the pillar for adjusting the direction of nozzle""s outlet. Further, an adjusting means is connected with the nozzle to drive the nozzle rotate about the axial pillars.